Underline coment tool - how to fix height position?

[br-lifestudent]

Hi guys,

I've been using PDF XChange Editor for some weeks after a decade using Foxit Reader and I'm liking it a lot but I'm facing an issue with the Underline comment tool that I'm not being able to fix.

The underline is usually too close to the characters, making it difficult to read the text, but when I underline a whole paragraph the underline gets progressively further from the characters with each line.

When I edit text then underline using CTRL+U it works as expect but it's not practical.

Bellow follow a screenshot using 'pdf gear' and 'pdf xchange editor' in both ways.

How can it be fixed?

[Stefan - PDF-XChange]

Hello br-lifestudent,

Welcome to our forums.

The position of the underline is determined by the font metrics, so it would be determined by the text on which you are applying that underline, and there is no way for you to tweak it's position relative to the text.
We are trying to use the same values as what other PDF software is using to keep things consitent, so this is unlikely to change much.

However your sample is a bit unusual - and the underlines should not be progresively going further away from the text itself.
So can you please share with us that sample page which you are trying to underline so that we can have a look?

Can you please also go to Help -> About inside the Editor and confirm which build is currently installed on your machine?


Kind regards,
Stefan

[br-lifestudent]

Hello br-lifestudent,

Welcome to our forums.

The position of the underline is determined by the font metrics, so it would be determined by the text on which you are applying that underline, and there is no way for you to tweak it's position relative to the text.
We are trying to use the same values as what other PDF software is using to keep things consitent, so this is unlikely to change much.

However your sample is a bit unusual - and the underlines should not be progresively going further away from the text itself.
So can you please share with us that sample page which you are trying to underline so that we can have a look?

Can you please also go to Help -> About inside the Editor and confirm which build is currently installed on your machine?


Kind regards,
Stefan

Hi,

Thank you so much for the quick answer.

It's 10.4.3 build 391.

The test page follows attached.

The Sleep Solution - W. Chris Winter, M.D_7.pdf

(56.02 KiB) Downloaded 83 times

[Stefan - PDF-XChange]

Hello br-lifestudent,

Thanks for the sample file!
After removing your underline and trying to place my own - mine appears to be placed exactly through the middles of the tails of the letters on each line. I tested with whole blocks of text as well as single lines at a time - and could not reproduce your behaviour.

Just to confirm - this happens when you try to place new underlines in the current Editor build and are not e.g. remnants that were placed with an older one?

I've shared my testing and findings with our devs and am awaiting their further feedback on this peculiar case!

Kind regards,
Stefan

[br-lifestudent]

Hi,

This odd behavior of underline getting progressively further from the characters on the paragraph didn't always happen but I've just updated the Editor and this issue seems to be fixed.

But there's something I would like to change: I would like the underline to be a little further from the words just like the 'pdf gear' example on the sample because having the underline a little further improves readability.

Is there an option (even if advanced) for that?

At.te.,

[Paul - PDF-XChange]

Hi, br-lifestudent

I believe this is dictated by the metrics of the font used and as such is not something we have controls to change.

[Arnold]

Perhaps using Squiggly Text and adjusting the Thickness Scale property would work for you. It does produce an "underline" that is a little further from the words.

Underline Properties.png (4.32 KiB) Viewed 3634 times

[Stefan - PDF-XChange]

Hello Arnold,

Thanks for the suggestion!
@br-lifestudent - hope that is useful for you!

As Paul said - the location of the underline is determined from the font metrics and is not adjustable with a variable that you can set, so I hope that the squiggly is an acceptable alternative, otherwise you can use the line tool with the Shift key to draw horizontal lines and you can then position them as far from the text as you desire.

Kind regards,
Stefan

[br-lifestudent]

Perhaps using Squiggly Text and adjusting the Thickness Scale property would work for you. It does produce an "underline" that is a little further from the words.

Underlined Text.png

Underline Properties.png

Thanks for the suggestion.
I tried it out and it has the perfect underline spacing but sadly it doesn't look good using other pdf readers like Sumatra.

Hello Arnold,

Thanks for the suggestion!
@br-lifestudent - hope that is useful for you!

As Paul said - the location of the underline is determined from the font metrics and is not adjustable with a variable that you can set, so I hope that the squiggly is an acceptable alternative, otherwise you can use the line tool with the Shift key to draw horizontal lines and you can then position them as far from the text as you desire.

Kind regards,
Stefan

Sorry but the line tool is not an option. It would damage my reading and studying by a lot.
Would the devs consider this underline spacing as an advanced option?

Att,

[Stefan - PDF-XChange]

Hello br-lifestudent,

This has been brought up in the past, but no - this option can not really be made adjustable and has to be fixed at a specific value (a percentage under the text base line), and we are using the same value as most of the other PDF software products out there to keep things consistent, so it is also not likely to be changed to a different value by our devs either.

Kind regards,
Stefan

[br-lifestudent]

Hello br-lifestudent,

This has been brought up in the past, but no - this option can not really be made adjustable and has to be fixed at a specific value (a percentage under the text base line), and we are using the same value as most of the other PDF software products out there to keep things consistent, so it is also not likely to be changed to a different value by our devs either.

Kind regards,
Stefan

That's a bummer. I was really liking using XChange but this is a big problem for me since I study a lot using pdfs and this underline spacing hurts my reading comprehension and speed.

I'm probably gonna stick to Foxit 8.3 since it was the last good version.

But thank you so much for trying to help me.

[Stefan - PDF-XChange]

Hello br-lifestudent,

Appreciate your feedback, however that spacing is not something we are looking at changing at this time, and of course you are free to use the tools that suit your specific needs.

Kind regards,
Stefan

[I-G-1-1]

Hi,

I have the same issue that's holding me from adopting PDF-XCHANGE in every day usage.

In reality I have 4 issue with your software:
1. the space between the text and the underline (as perfectly explained in this thread by br-lifestudent);

2. the width and the border shape of the highlight;

3. the fact that if I open in PDF-XCHANGE a PDF already commented with underline/highlight in Drawboard-PDF (with perfect underline spacing and hightlight width) then PDF-XCHANGE render the file with its space between the text and the underline and also its width and its border shape of the highlight;

4. the fact that If:

• I open in PDF-XCHANGE a PDF already commented with underline/highlight in Drawboard-PDF (with perfect underline spacing and hightlight width)

• only view a page with underline/highlight from Drawboard-PDF

• add a bookmarks to the page

• save the files

then: all the underline/highlight I made in Drawboard-PDF years ago now have the space between the text and the underline and also the width and the border shape of the highlight changed by PDF-XCHANGE.


I understand that you are trying to use a "standard" but would be great If you could insert in preferece/comments the ability to choose:

• a personalized value for the space between the text and the underline

• a personalized value for the width of the highlight

• the shape for the border of the highlight

Here is some example of how bad your software is rendering the underlines and the highlights compared to Drawboard-PDF:

As last thing I would point that the final answer from the Admin Stefan to a user asking for improovment

"...and of course you are free to use the tools that suit your specific needs..."

it's really a bad approach for a company that has as core business the sale of a software. So please don't middle finger like that your valued user, because if your users found a PDF software better than yours then they will spread the voice and you'll loose potential clients and market share. For example I was a Drawboard-PDF user and I found your product through word of mouth, thanks to some posts on reddit's /Surface.

[mCHSNUg5Pz8cPap]

I don't use underline much so I haven't noticed this issue. However, after doing a bit of testing, I think the above posters have a legitimate complaint. Here is the result of my test:

The underlining is too close to the text.

This has been brought up in the past, but no - this option can not really be made adjustable and has to be fixed at a specific value (a percentage under the text base line), and we are using the same value as most of the other PDF software products out there to keep things consistent, so it is also not likely to be changed to a different value by our devs either.

Is this standard published somewhere? I'd like to review it.

Edit to add: I looked through the PDF specification and found this about underlining:

I don't see anything in there about it specifying that the underline must be at a specific percentage under the text base line or that there is an agreed upon value used by most pdf software products.

[Sean - PDF-XChange]

Hi all,

I'm afraid we can only reiterate what has already been mentioned above - the space between font and underlines is dictated by the font being used. This is something that is out of our control, and it's not going to change.

Kind regards,

[mCHSNUg5Pz8cPap]

Hi all,

I'm afraid we can only reiterate what has already been mentioned above - the space between font and underlines is dictated by the font being used. This is something that is out of our control, and it's not going to change.

Kind regards,

Even though this has been said repeatedly in this thread, I think it is incorrect. The underline that is provided with a font is different than the underline that is provided as a comment. The former is part of the base content and the distance from the underline to the text is dictated by the font. The latter is not part of the base content and is instead part of the pdf comments so the distance from the underline to the text is not dictated by the font.

The following image illustrates this. The black underline in the image was created using Edit Text → select the text with mouse cursor → select format tab → click underline button. The black underline is part of the font, which is part of the base content. The purple underline was created using the "Underline Text Tool." I selected the text with the tool and it underlined it purple.

.
As you can see, the underline that is built into the font and part of the base content is further away from the text than the underline provided by the Underline Text Tool, which is part of the comments layer. They clearly do not follow the same spacing requirements. Nor is there anything that says underlining inserted as a comment needs to conform to the same requirements as underlining provided as part of the font (the image above shows this is clearly not the case!).

[I-G-1-1]

Hi all,

I'm afraid we can only reiterate what has already been mentioned above - the space between font and underlines is dictated by the font being used. This is something that is out of our control, and it's not going to change.

Kind regards,

Sorry but this is absolutely not true and shows a lack of knowledge in the PDF format.

You can "comment" a PDF wich means that you can add annotation like highlight, underline over the text.

It doesn't have anything to do with the specific font.

I don't like it, but some app like "PDF Annotator" even uses a different layer for the annotation.

Please escalate this issue to someone that normally deals with PDF annotations because clearly you don't know what we are referring to.

And sorry but have to explain this to an employee of a PDF app with annotation capabilities it's really disarming.

[Stefan - PDF-XChange]

Hello I-G-1-1,

Yes maybe there was an incorrect expression earlier.
The spacing is within our control, however it is hard coded and is not something that we are considering changing or allowing control over, sorry!

Kind regards,
Stefan

[I-G-1-1]

The spacing is within our control, however it is hard coded and is not something that we are considering changing or allowing control over, sorry!

Until you decide to fix this issue for me (and I think a lot of people that uses PDF highlight/underline for work or study) your program is BROKEN, and I'll delete it from my tools and for sure I'll not endorse your software to anyone that use a Surface Pro to work/study with PDFs.

I find it very short-sighted not to please your users on fix a feature that a lot of users are reporting to you as BROKEN.

[Stefan - PDF-XChange]

Hello I-G-1-1,

This particular spacing is a matter of preference, and we've chosen a value that appears to most closely match that used by the PDF tool that has the largest user base. So while your preference is different, unfortunately at this time we are not looking at changing that spacing, and while we are sorry you feel that way - changing it to your liking will make a larger number of people unhappy. Sometimes when we can not please everyone, and a specific setting is better left non user customizable we need to look for the option that will suit the majority.

Kind regards,
Stefan

[mCHSNUg5Pz8cPap]

This particular spacing is a matter of preference, and we've chosen a value that appears to most closely match that used by the PDF tool that has the largest user base.

Does PDF-XChange use the same underline spacing as Acrobat?
Here is a test file with text I OCR'd with PDF-XChange:

10256352.pdf

(124.22 KiB) Downloaded 11 times

.
Here is what it looks like when underlined with Acrobat Reader AND viewed in Acrobat Reader:

.
Here is what it looks like when underlined with Acrobat Reader AND viewed in PDF-XChange (I think it looks the same as when it is viewed in Acrobat Reader):

.
Here is the same text underlined using the underline feature in PDF-XChange:

.
The underline in PDF-XChange is closer to the text than that produced by Acrobat Reader. I understand that the developer thinks they are the same, but they are not. At least with Adobe, there is enough space that it visually does not look like the underlining is touching the bottom of the text like it does with PDF-XChange.

Here are the files with the underlining used to create the above screenshots.

10256352_PDFXChange.pdf

(126.36 KiB) Downloaded 3 times

10256352_AcrobatReader.pdf

(127.63 KiB) Downloaded 6 times

[rakunavi]

Hello all,

The underline in PDF-XChange is closer to the text than that produced by Acrobat Reader. I understand that the developer thinks they are the same, but they are not. At least with Adobe, there is enough space that it visually does not look like the underlining is touching the bottom of the text like it does with PDF-XChange.

I was thinking the same thing. I would also like to add that the situation is different between Latin fonts and Japanese fonts. As @mCHSNUg5Pz8cPap commented about Latin fonts (Arial, Times New Roman, etc.), but for Japanese fonts (MS Ghothic, Yu Gothic, etc.), the height position of underline height is the same between PDF-XChange Editor and Acrobat. The same tendency can be seen in other Japanese fonts. Maybe this is true not only for Japanese fonts, but for all fonts except Laten fonts. Therefore, when considering this issue, it might be better to take into account the language used by the user, and the situation might differ depending on the font used.

A sample file with underline annotations in PDF-XChange Editor and Acrobat Reader is attached for your reference. A partially enlarged figure is shown below. Note that the situation is different for the top two Latin fonts and the bottom two Japanese fonts.

• 

  For Latin fonts (Arial and Times New Roman), the height position differs between PDF-XChange Editor and Acrobat.
  For Japanese fonts (MS Gothic and Yu Gothic), the height position is the same between them.

• sample.pdf

  (10.52 KiB) Downloaded 15 times

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.5.2 build 395
- Adobe Acrobat Reader Continuous Release Version 2025.001.20435 (64-bit)
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.3476
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Stefan - PDF-XChange]

Hello rakunavi, and all,

Thanks for showing those comparisons! I've asked our devs to take another look at this and review what we can do with these underlines and their spacing from the text!

Kind regards,
Stefan